Uninegative multicolor planography



mama May 14, 1940 UNITED STATES amass namesanva m'ncotoa rmocaarnr filutsvc a. Lukcsh, Pasadena, Calif., as John G.

. v(ioedike, San Antonio, Tom

10 Drawing. Application April 13, 1989, a Serial No. 267,676

7 Claims.

(Granted under the act of March 3, 1883, as

This invention described'herein may be manufactured and used by or for the Government for governmental purposes. without the payment to us of any royalty thereon.

, This invention relates to a process of multicolor reproduction from planographic and other analogous printing presses and in the present case is called uninegative multicolor planography, as only one photographic negative is 10 used in the process to obtain several pianographic or photolitho process press plates of progressive color value for the reproduction of the original copy in multicolor.

- This process may be used for the reproduction of any subject or original copy in multicolor and is particularly valuable as a method of reproducing such single hued copy as air pictures, air mosaics, wash drawings and photographic copy in multicolor by the planographic process. It is known that the use of color filters and the circular screen will obtain photographic negatives of distinct color values from any colored copy, but by this process it is possible to supply color values for single hued copy and from one photographic negative.

Monochromatic pianographic reproduction of any pictorial subject of a single hue will give a very flat resultor a result that has lost much of the detail if any contrast is obtained. It is cona templated by this invention to use a single photographic negative of normal exposure and development to obtain several and distinct pianographic press plates of progressive color value to be run in colors, varying from a light color a such as yellow to a dark blue, and obtain a multi-colored reproduction of the subject.

Treatment in this manner will permit the introduction of an increase in the qualities of form I and relief; intensification and clarification of features and detail; embellishment; introduction of color contrast, color harmony, and/or color complement as desired.

. In carrying out the invention, the process consists in producing a single photographic negal tive of normal exposure and development of a pictorial subject to be reproduced in multicolors. A contact positive may be made of the negative and then a master negative of the same size as a planographic plate may be made of the posiso tive.

To produce a multicolor reproduction of the subject from the master negative, a plurality of time controlled exposures of the negative is made upon a plurality of planographic plates s which are treated progressively, each plate beins .amended April 30, 1928; 370 0. G.

grained to the correct texture for the color intended. The surface of the plate for the lightest color such as yellow receives the finest grain. The surface of the plate or plates for the intermediate colors such as red and the like, receives 5 a grain coarser in texture than the plate for the lightest color and the surface of the plate for the darkest color such as dark blue receives the coarsest grain in the series, whereby progressive light sensitive coatings of varying sensitivity are 10 provided on the plates.

In order to aid in obtaining progression in the light sensitive coatings on the plates of the series, suitable light sensitive solutions may be used on the light sensitive coatings with the ex- 16 posures of the negative to the plates being timed with respect to the sensitivity of the light sensitive solutions. The solutions are selected with respect to the sensitivity of the light sensitive coatings on the plates, and as an example the following formulae may be used to obtain progression in the light sensitive coatings on the plates of the series as above described. It is to be understood, however, that these formulae are given without intending to confine the process a to the formulae.

To give an extremely light sensitive coating to a plate, the first solution may be composed follows:

Water fluid ounces Egg albumen flakes ounces 16 Ammonium bichromate do 3 Aqua ammonia, 28% fluid ounces 3 a To give a less sensitive coating to a plate which develops easily, the second solution may be composed as follows:

Water fluid ounces 160 40 Photoengravers glue do 32 Ammonium bichromate ounces 3 Aqua ammonia, 28% fluid ounces .3

The plate for the lightest color of the series 45 may be coated in the usual manner with the first solution and in a vacuum frame under the negative it is given extreme exposure to light. All the modeling, in the light tones of the subject, is burned on to this plate and the modeling in the dark shadows is disregarded and will go solid and lose character.

The plate for the intermediate color of the series may be coated with a composite solution which is proportioned of the two solutions given and mixed as follows:

Fluid ounces 1st solution (albumen) 14 2nd solution (glue) 2 lst solution (albumen) 12 2nd solution (glue) 4 This plate may be exposed under the negative in the vacuum framein the usual manner and the exposure to the light timed to obtain the detall in the deep tones of the subject. All the detail in the light tones of the subject are lost from the surface of this plate but some of the intermediate tones will hold.

The plates after exposure to the negative may then be treated for use on a press, such as by coating the plates of the series with developing ink and developing them under water, and after developing flowed with a thin solution of gum arabic which contains a trace of a suitable acid, such as phosphoric, and placed in the whirler to dry with the heat on. Drying in a temperature between to degrees F. seasons the design on the surface of a plate and it becomes resistant enough to stand an acid treatment for fixation.

Each plate may then be allowed to cool after drying and heating and then soaked under water for a few minutes to soften the gum coating and rinsed with water, then without being permitted to dry it is flowed with a weak solution of hydrofluoric acid in water. The action of the hydrofluoric acid is to eat away all dead or exposed albumen which might tint up on the press.

After treatment with hydrofluoric acid the plate surface could be flowed with a thin desensitizing solution of gum arabic and phosphoric acid and dried in the whirler. The plate is then ready for the press.

Depending on the subject and the color *eflect desired the number of progressive color plates may be increased from three to as many as may be required. In making a three color separation from one negative the light color plate of the series will register detail from the lightest tones to a point between the quarter and half tones, the intermediate color plate will register detail from a point between the quarters and half tones to a point between the half and three quarter tones and the dark color plate of the series will register detail from a point between the half and three quarter tones to the full tone.

The developed light sensitive surfaces of the plates are coated with inks of varying color selected with respect to the sensitivity of the corresponding light sensitive surface, thereby providing a plurality of separate and distinct planographic press plates of progressive color value to be run in colors varying from a light yellow to a dark blue, which may be impressed on a printing surface in proper sequence to supply tone effects of primary, secondary and tertiary colors to the reproduced subject.

The process above described is based partly on the discovery that a light sensitive coating for metal planographic press plates may be gov- 6 erned so that the light sensitive properties can be varied from high to low contrast as desired. This effect of degree of contrast is common to sensitive photographic plates and film, but it is new to take advantage of the sensitive degree 10 of the coating on metal planographic plates for the purpose of color separation. The process is further based on the discovery that (with or without such control of light sensitive coating), by controlling the number of plates, by selecting the appropriate grain for each plate, by controlling the exposure of the light-sensitive coatings to light, by selecting appropriate colors and tones of inks and developing the exposures, a result of color separation and/or color superimposition is achieved, producing a print in selected and controlled colors, all from a single original negative, without recourse -to color filters.

The use of one negative for making the progressive color plates precludes the possibility of 25 distortion, as each plate will register perfectly to the other plates of the series.

As many progressive color plates may be used as the subject and the desired color effect require. The color scheme will govern the color of 80 the impression for each plate of the series.

It will thus be seen there is provided a highly useful and emcient process for the reproduction in multicolors of an original copy from a single photographic negative. Even though there have 5 herein been described certain steps in carrying out the process, it is nevertheless to be understood that various changes may be made therein without departing from the spirit or scope of the invention.

Having describedour invention, what we claim as new and wish to secure by Letters Patent is:

l. A process for making a multicolor reproduction from a single monochromatic original which consists in making a plurality of variably timed l6.

exposures of said original upon a succession of light sensitive surfaces, each surface having a diflerent sensitivity than the others thereof, varying from a slight sensitivity to an extreme sensitivity, the sensitivity of the surfaces being related 50 to the colors intended and the timing of the exposures of said original upon said light sensitive surfaces being directly related to the sensitivity of said surfaces, developing said exposed light sensitive surfaces to form a plurality of printing- 6 surfaces, coating said developed light sensitive surfaces with inks of variable color selected with respect to the sensitivity of said surfaces and with respect tothe timing of the exposures of said original upon said light sensitive surfaces and successively impressing each of said coated surfaces in proper sequence upon a receiving surface.

2. A process for making a multicolor reproduction from asingle monochromatic original which comprises making a plurality of variably timed exposures of said original upon a succession of light sensitive surfaces of variable color sensitivity, each surface having a different color sensitivity than the others thereof, varying from a 70 slight color sensitivity to an extreme color sensitivity, the sensitivity of the surfaces being related to the colors intended, and the timing of the exposures of said original upon said light sensitive surfaces being directly related to the color 1 sensitivity of said surfaces, developing said exposed light surfaces to form a plurality of printing surfaces, coating said developed light sensitive surfaces with inks of variable color selected with respect to the sensitivity of said surfaces and with respect to the timing of the exposures of said original upon said light sensitive surfaces and successively impressing each of said coated surfaces in proper sequence upon a receiving surface.

3. A process for making a multicolor reproduction from a single monochromatic original which comprises making a plurality of variably timed exposures of said original upon a succession of light sensitive surfaces of variable sensitivity, varying from a slight sensitivity to an extreme sensitivity, each of said surfaces being differently grained fromthe others thereof varying from a fine grain to a coarse grain, the colors being selected with respect to the graining of said plates, the sensitivity of said surfaces being related to the graining thereof and the timingof the exposures of said original upon said light sensitive surfaces being directly related to the graining of said surfaces, developing said exposed light sensitive surfaces toform aplurality of printing surfaces, coating said developed light sensitive surfaces with inks of variable color selected with respect to the graining of said light sensitive surfaces and with respect to 'the timing of the exposures of said original upon said light sensitive surfaces and successively impressing each of said coated surfaces in proper sequence upon a receiving surface.

4. A process for making a multicolor reproduction from a single monochromatic original which comprises making a plurality of variably timed exposures of said original upon a succession of planographic plates having light sensitive surfaces of variable sensitivity, each surface of said plates having a different sensitivity than the others thereof varying from a slight sensitivity to an extreme sensitivity, the sensitivity of the surfaces being related to the colors intended and the timing of the exposures of said original upon said light sensitive surfaces of said plates being directly related to the sensitivity of said surfaces, developing said exposed light sensitive surfaces on said plates to form a plurality of printing surfaces, coating said exposed light sensitive surfaces of said plates with inks of variable color selected with respect to the sensitivity of said surfaces and the timing of the exposures of said original upon said light sensitive surfaces, and successively impressing each of said coated surfaces of said plates in proper sequence upon a receiving surface.

5. A process for making a multicolor reproduction from a single monochromatic original which comprises making a plurality of variably timed exposures of said original upon a series of planographic plates, each plate being differently grained from the others thereof varying from a fine grain to a coarse grain, whereby progressive depth of light sensitive coatings is provided on the plates, the sensitivity of said light sensitive coatings on said plates being related to the graining of said plates and the colors intended and the timing of the exposures'of said original upon said light sensitive coatings of said plates being directly related to the sensitivity of said coatings. developing said exposed light sensitive coatings of said plates to form a plurality of printing surings of said plates with inks of variable color selected with respect to the sensitivity of the light sensitive coatings and with respect to the timing of the exposures of said original upon said light sensitive coatings and successively im- 5 pressing each of said light sensitive coatings of said plates in proper sequence upon a receiving surface.

6. A process for making a multicolor reproduction of a subject from a single photographic 10 negative which comprises graining a series of planographic plates to obtain progressive depth of light sensitive coatings on the plates, each plate having been differently grained from the others thereof varying from a fine grain to a coarse 15 grain, coating the light sensitive coatings of said plates with light sensitive solutions of variable sensitivity selected with respect to the sensitivity of the light sensitive coatings on the plates, whereby light sensitive surfaces are provided on 20 the plates of variable sensitivity, making'a plucolors intended and the timing of the exposures of said negatives upon said light sensitive surfaces being directly reiated to the sensitivity of said surfaces, developing said light sensitive surfaces to form a plurality of printing surfaces, 30 coating said developing light sensitive surfaces with inks of variable color selected with respect to the graining of said plates and sensitivity of said surfaces and with respect to the timing of the exposures of said negative upon said light sensi- 35 tive surfaces and successively impressing each of said coated surfaces of said plates in proper sequence upon a receiving surface.

7. A process for making a multicolor reproduction from a single photographic negative which 40 comprises progressively graining a series of metal planographic plates to the correct texture of the color intended, varying from a fine grain to a very coarse grain, thereby obtaining progressive depth of light sensitive coatings of variable sensi- 4s tivity on said plates, the sensitivity of the light sensitive coatings being related to the graining of said plates and the colors intended, the finer the grain of said plates the lighter the colors intended, making a plurality of variably timed ex- 5 posures of said negative in succession upon the light sensitive coatings of said plates, controlling the timing of the exposures to light of said negative upon the light sensitive coatings of said plates, the finer the grain of said plates the more as the time interval of exposure of said negative to the light sensitive coatings on said plates, the timing of the exposures of said negative on said light sensitive coatings of said plates being diof said negative upon said'light sensitive coatings JOHN G. GOEDIKE. 

